Methylenetetrahydrofolate Dehydrogenase (NADP)

**Definition:** An NADP-dependent oxidoreductase that catalyses the conversion of 5,10-methyleneterahydrofolate to 5,10-methenyl-tetrahydrofolate. In higher eukaryotes a trifunctional enzyme exists with additional METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE and FORMATE-TETRAHYDROFOLATE LIGASE activity. The enzyme plays an important role in the synthesis of 5-methyltetrahydrofolate, the methyl donor for the VITAMIN B12-dependent remethylation of HOMOCYSTEINE to METHIONINE via METHIONINE SYNTHETASE.

**Tree numbers:** - D08.811.682.662.253

**Synonyms:** - Methylenetetrahydrofolate Dehydrogenase - Methylenetetrahydrofolate Dehydrogenase (NADP+)